This paper describes a high side voltage controller (HSVC) design, implementation and
performance study for a synchronous generating unit connected to an infinite bus power system
via a transformer and a double-circuit transmission line. In addition to enhance the system
performance, the HSVC can improve power system voltage stability by adding supplemental
control to conventional generator excitation system. The simulation results using detailed non‌linear model for the system with: a conventional automatic voltage regulator (AVR), power system
stabilizer (PSS), and applying HSVC, are obtained. These results illustrate the superiority of
HSVC to enhance the system performance as well as its voltage stability when subjected to
different disturbances